Double acting buffer for weaving looms



Dec. 1, 1959 J. PlCANOL 2,915,093

DOUBLE ACTING BUFFER FOR WEAVING LOOMS Filed Nov. 1, 195a 2 Sheets-Shat 1 1. Pic an o I. IIVVfNTO/P A TTORNEYI Dec. 1, 1959 J. PICANOL 2,915,093

DOUBLE ACTING BUFFER FOR WEAVING LOOMS Filed Nov. 1, 1956 I 2 Sheets-Sheet 2 I a f mmm@ I l5 I6 74 a PLccLnal, am-wrae A I'TQRIVA'YI United States Patent C) DOUBLE ACTING BUFFER FOR WEAVING LOOMS Jaime Picanol, Zillebeke-lez-Ypres, Belgium Application November 1, 1956, Serial No. 619,784

Claims priority, application Belgium December '17, 1955 1 Claim. (Cl. 139-188) It has hitherto been assumed, that looms with a fastreed, i.e. looms with buffers, were unsuitable for very high speed operation, and that such high operating speeds could only be obtained when looms with a mobile reed were resorted to. Though looms with a mobile reed undoubtedly offer certain advantages, they are also affected with serious drawbacks. The most important of these drawbacks, which indeed already in itself would constitute a sufficient ground for rejection in many cases, resides in the fact, that it is not possible, with such looms, to manufacture relatively heavy or dense fabrics, i.e. requiring forceful beating home of the weft. On the other hand it is also required, in such looms, to firmly lock the reed supporting frame, which must be repeated for each pick, and this can only be obtained with the aid of a rather delicate mechanism, which is subject to wear. However, a drawback of looms with a fast-reed is that they may easily give rise to cracks, whenever they are operated at a very great speed.

It is the purpose of the invention to provide a buffer of novel design, whereby the use of looms with a fastreed at high speeds is systematically warranted. The main feature of this novel buflfer resides in the fact, that, in contrast to the buffers as hitherto proposed, it is double-acting and so arranged, that the production of such enormous impact forces as would cause cracking or breaking of either the lathe uprights or parts of the frame work is entirely eliminated.

Another feature of the arrangement according to the invention relates to carefully positioning the various moving elements in such a way that at the instant the buffer is struck, no forces are transmitted to the upright. This has been arranged, according to the invention, by slightly lowering the crank shaft with respect to its usual position in looms of known design. This disposition of the crank shaft enables to ensure, that at the very instant the loom butts, i.e. when the lathe strikes against the buffer, the centre of the crank pin, the centre of the connecting rod small end, the centre of the bush of the stop rod nose and finally the point of said stop rod nose are exactly in line. Said points are therefore all in a straight line at the very instant the loom butts, so that no vertical component acts upon the lathe upright, whereby the latter is safeguarded against such detrimental effects of fatigue, as are mainly responsible for the formation of cracks.

Still another feature of the novel buffer resides in the fact, that for realising said double action, use is only made of one spring, which is an important point in that it affords a very compact construction and consequently a considerable reduction of the space occupied by said buffer. All of said features will be brought out more clearly hereinafter in a detailed description of a nonrestrictive example of an embodiment, as shown in the appended drawings, wherein:

Figure 1 is a schematical side view showing the essential elements of a loom as will enable it to locate the double-acting buffer of the invention;

2,915,093 Patented Dec. 1, 1959 'ice Figures 2, 3 and 4 schematically show longitudinal sections of the buffer in three characteristic positions;

Figure 5 schematically represents the relative position of the point of the stop rod nose, the centre of the bush of said stop rod nose, the centre of the connecting rod small end and the centre of the crank pin.

According to the invention, the buffer substantially consists of a hollow body 1 carrying the stop element 2 at the back side of its top. Said hollow body 1 has at its forward and its backward end openings 3-4 each formed with a shoulder, 5 and 6, respectively, facing towards the inside of said hollow body. Fitted in said openings 3--4, so as to slide therein with gentle friction, are stop rings 7 and 8, respectively, both mounted on a common spindle 9 between a head 10 and a nut 11, said nut being screwed on a corresponding threaded portion of said spindle 9 and locked in position by a lock nut 12. Within the hollow body, surrounding said spindle 9, is disposed a relatively very powerful helicoidal spring 13 being so dimensioned as to simultaneously bear, with one end on the inwards facing shoulder 5 and on the stop ring 7, and with its other end on the inwards facing shoulder 6 and the stop ring 8. A restoring spring 16 is placed between a projecting portion 14 of the hollow body 1 and a fixed support 15.

Normally the buffer is in the position as schematically indicated in Figure 2, in which the duly calibrated spring 13 rests half on the inwards facing shoulders of the hollow body 1 and half on the stop rings 7--8. The stop rod nose 17 is in a retracted position. When the stop rod nose 17 forcefully strikes the stop element 2, as schematically indicated in Figure 3, the hollow body 1 of the buffer is projected, against the action of the spring 13 which presses against the inward shoulder 5, thus acting as a shock absorber. As said body of the buffer is shifted backward with respect to the stop rings 7-8, the spring 13 bears, at its foremost end, only upon the shoulder 5 of the hollow body, and at its hindmost end only upon the stop ring 8. As a result, when the stop rod nose 17 is again retracted due to the forward movement of the batten, the body of the buffer thus released is thrown back with force by the action of said spring 13 and reaches the position as schematically indicated in Figure 4, in which the spring 13 exclusively bears with its forward end on the stop ring 7, and with its backward end on the shoulder 6 of the buffer body. Finally said buffer reverts to its normal rest position, as shown in Figure 2.

It will be appreciated, that the buffer acts in one direction as efliciently as' in the opposite direction, while using the same interior spring 13 in both cases.

The second characteristic feature of the invention relating to the buffer is schematically indicated in Figure 5, from which it appears that by slightly lowering the crank shaft it has been possible to adjust the centre 18 of the crank pin, the centre 19 of the connecting rod small end, the centre 20 of the bush of the stop rod nose and the point of said stop rod nose on a straight line A-B, the instant that the loom butts.

Apparently the various features as hereinbefore described may be realized in other forms than those described and illustrated in the drawings. Particularly, the unique relatively powerful spring 13 hearing simultaneously on parts of the body of the buffer and on stop elements adjacent said parts, said stop elements may be made in any shape and in any appropriate way. Likewise, the alignment feature as described above may be applied in mechanisms and looms of any kind.

What I claim is:

A double-acting buffer for weaving looms, said buffer comprising a hollow body movable from a position of rest to a rearward position, thence to a recoil position and back to the rest position, said hollow body having alined openings formed in the front and back faces thereof and rearwardly facing front and back annular shoulders adjacent said openings, at spindle extending through both openings of said hollow body, two stop elements slidingly adjusted on said spindle and fitted in said openings so as to slide therein, and a coiled spring surrounding said spindle and located within said hollow body, said spring having a front end surface engaging both one of said stops and said front shoulder and a rear end surface engaging both the other one of said stops and said rear shoulder in said rest position, said front end surface of the spring engaging solely said front shoulder and said rear end surface of the spring engaging solely said other stop in said rearward position, and said front end surface of the spring engaging solely the first-mentioned stop and said rear end surface of the spring engaging solely said rear shoulder in said recoil position, whereby a double-acting eifect is attained.

Welti Apr. 18, 1944 Picanol Apr. 16, 1955 

